U.S. health officials on Friday approved the first medicine for treating the late stages of Alzheimer's, the degenerative brain disease that afflicts an estimated 4 million Americans. Namenda, made by Forest Laboratories Inc., slowed the decline in awareness, reasoning and daily function experienced by patients with moderate to severe Alzheimer's who were treated in clinical trials, the Food and Drug Administration said.

Alzheimer's is not slowed by taking anti-inflammatory drugs, according to a yearlong study of people in the early stages of the brain disease, quashing hopes from other evidence that the therapy might be beneficial. The finding, reported today in the Journal of the American Medical Assn., compared the progression of Alzheimer's in 351 patients given either a placebo or one of two anti-inflammatory drugs -- naproxen or rofecoxib.

The brain-destroying illness that killed a man who had eaten venison and elk meat was not a form of chronic wasting disease affecting deer herds, state health officials said Thursday. Wisconsin's Division of Public Health has been investigating the deaths of three outdoorsmen to find out whether chronic wasting disease crossed from animals to humans, just as "mad cow" disease did in Europe.

Ric and Myrna Hansen became elk ranchers three years ago so they could raise animals without having to kill them. So it wasn't a hard decision to turn down a recent buyout offer from the U.S. Agriculture Department. To accept would have been to condemn their 700-head herd to slaughter as officials try to stop a deadly deer and elk disease. The Hansens, who raise elk as breeding stock, concede that their decision is risky.

Scientists have long sought to understand a horrific brain disease that once devastated the native people of Guam--Lou Gehrig's, Alzheimer's and Parkinson's symptoms rolled into one. Now two researchers have uncovered clues that suggest a Chamorro dietary tradition--eating a type of bat that feeds on neurotoxic plants--might be behind the mystery illness. It's circumstantial evidence so far.

Two sheep, seized from a Vermont farm by U.S. government officials last year, tested positive for a family of rare, brain-deforming animal diseases that includes scrapie and mad cow disease, the U.S. Department of Agriculture said Thursday. The USDA said tissues from the infected sheep were found to have a foreign strain of a transmissible spongiform encephalopathy disease, but the type of TSE was not yet known.

A snippet of tissue in the brain's frontal lobe has become the focus of science's quest to find exactly where we get our sense of who we are. Several recent experiments pinpoint the lobe's right hemisphere as the locus of our identity. The study of brain diseases has been a factor in illuminating the research into "self." People who seem to have lost their sense of self are now said to be suffering from a condition called frontotemporal dementia.

With a second case of "mad cow" disease confirmed in Japan, the government said Thursday it will slaughter and incinerate 5,100 cows that may have been fed ground animal parts. The Agriculture Ministry could begin the measures nationwide as early as next week, said Satoshi Maema, an official at the ministry's Animal Health Division.

About 1,000 elk in three private Colorado herds were found to be infected with a brain ailment called chronic wasting disease and will be destroyed and tested. One herd is in south-central Colorado, raising concerns the disease could spread into the state's renowned Western Slope elk and deer herds, according to the Colorado Division of Wildlife. The others are in the north, where the disease has been present for decades.

Japan's government announced Monday that it has found the country's--and Asia's--first suspected case of "mad cow" disease and blamed imported feed as the likely cause. Japanese health experts had previously asserted that the high standards of cleanliness at Japanese cattle ranches would keep the country free of the brain-wasting disease, which has ravaged herds in Britain and elsewhere in Europe and is believed to be linked to a fatal human disease.